As we write this commentary while under stay-at-home orders (two of us in the U.S., and the other in Germany), the number of individuals infected with the SARS-CoV-2 coronavirus has surpassed 1.6 million confirmed global cases and more than 95 000 fatalities. The pandemic continues to spread exponentially in all regions of the world. The trajectory and ultimate outcome of this pandemic is still unfolding but we can already be certain that the consequences to life and livelihood throughout the world will be enormous. We have spent much time during our careers focused on efforts to prevent catastrophic process safety events, which are typically characterized as having both very high impact and very low probability/frequency. There are strong parallels between prevention of catastrophes in chemical process safety and prevention of catastrophic pandemics, beginning with the concepts of loss of containment/loss of control of hazards. The steps for risk analysis and risk acceptance are similar. Those analyzing risks for either a pandemic or a process safety incident must envision/describe scenarios related to a specific hazard(s). Risk is a function of the magnitude of the impact and the likelihood of occurrence of the event. If the risk is deemed to be above the risk tolerance threshold, action is required to reduce the risk. Once scenarios (causeconsequence pairs) are developed, planners must decide which scenarios are credible events and further, which scenarios carry a risk. If the risk-tolerance threshold is exceeded, risk-based decisions must be made to implement appropriate safeguards including both (a) preventive safeguards to reduce the probability of a loss of containment/control incident and (b) mitigative safeguards to reduce the consequences should loss of containment/control occur. The modern concept of Black Swan events was developed by Nassim Taleb in his 2007 book entitled The Black Swan, The Impact of the Highly Improbable. According to Taleb, a Black Swan event has three attributes: “First, it is an outlier, as it lies outside the realm of regular expectations, because nothing in the past can convincingly point to its possibility. Second, it carries an extreme impact (unlike the bird). Third, despite its outlier status, human nature makes us concoct explanations after the fact, making it explainable and predictable.” Application of the Black Swan concept to process safety was advanced in a 2012 article in Process Safety Progress entitled “Beware of the Black Swan: The Limitations of Risk Analysis for Predicting the Extreme Impact of Rare Process Safety Incidents”. While there have been true Black Swan events in process safety in the history of the chemical process industries (CPI), there have also been many severe but rare events which were either foreseen or were predictable based on known science and experience. These identified/predictable events do not satisfy the first of Taleb's three qualifying criteria for a Black Swan—that nothing in the past can convincingly point to its possibility. Since the publication of Taleb's popular book, the term Black Swan has come into much more common usage by risk management professionals and others—perhaps to the point of being misapplied and overused. In an award-winning Actuarial Society presentation, Werther acknowledged that when using current risk assessment and forecasting methods in the financial and insurance industries, there are true Black Swan events. However, he also asserts that some events widely perceived as Black Swans are being “wrongly labeled”. They were in his view predictable. Based on our experience in dealing with low-frequency (rare) high-impact scenarios in chemical process safety, we were asked our opinion as to whether the current COVID-19 pandemic should be classified as a Black Swan event. Although the timing of its appearance and exact nature of this specific SARS-CoV-2 coronavirus had not been predicted, experts in infectious disease/public health protection have been warning us for Received: 8 April 2020 Revised: 10 April 2020 Accepted: 13 April 2020

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COVID-19 大流行：它是“黑天鹅”吗？与化学过程安全相关的一些风险管理挑战

当我们在居家令下（我们两个在美国，另一个在德国）撰写此评论时，感染 SARS-CoV-2 冠状病毒的人数已超过 160 万确诊的全球病例，甚至更多超过 95 000 人死亡。大流行继续在世界所有地区呈指数级蔓延。这种流行病的轨迹和最终结果仍在展开，但我们已经可以肯定，对全世界的生活和生计造成的后果将是巨大的。在我们的职业生涯中，我们花了很多时间专注于预防灾难性过程安全事件，这些事件的典型特征是具有非常高的影响和非常低的概率/频率。化学过程安全中的灾难预防与灾难性流行病的预防之间有很强的相似之处，首先是失去遏制/失去对危害控制的概念。风险分析和风险接受的步骤是相似的。分析大流行或过程安全事件风险的人员必须设想/描述与特定危害相关的情景。风险是影响程度和事件发生可能性的函数。如果认为风险高于风险容忍阈值，则需要采取措施降低风险。一旦制定了情景（因果关系对），规划者必须决定哪些情景是可信的事件，以及哪些情景具有风险。如果超过风险承受阈值，必须做出基于风险的决策以实施适当的保障措施，包括 (a) 预防性保障措施以减少发生遏制/控制事件损失的可能性，以及 (b) 减轻遏制/控制损失发生时的后果的缓解性保障措施。黑天鹅事件的现代概念是由纳西姆·塔勒布 (Nassim Taleb) 在其 2007 年题为《黑天鹅，极不可能事件的影响》一书中提出的。根据塔勒布的说法，黑天鹅事件具有三个属性：“首先，它是一个异常值，因为它超出了常规预期的范围，因为过去的任何事情都不能令人信服地指出它的可能性。其次，它具有极大的冲击力（与鸟不同）。第三，尽管处于异常状态，但人性使我们事后编造解释，使其具有可解释性和可预测性。” 黑天鹅概念在过程安全中的应用在 2012 年《过程安全进展》的一篇题为“小心黑天鹅：预测罕见过程安全事件极端影响的风险分析的局限性”的文章中得到了推进。虽然在化学加工工业 (CPI) 的历史上确实发生过过程安全方面的黑天鹅事件，但也有许多严重但罕见的事件，这些事件要么是可预见的，要么是根据已知的科学和经验可以预测的。这些已确定/可预测的事件不满足塔勒布关于黑天鹅的三个资格标准中的第一个——过去的任何事情都不能令人信服地指出它的可能性。自从塔勒布的畅销书出版以来，“黑天鹅”一词已被风险管理专业人士和其他人更普遍地使用——也许到了被误用和过度使用的地步。在屡获殊荣的精算学会演讲中，维特承认，在金融和保险行业使用当前的风险评估和预测方法时，确实存在黑天鹅事件。然而，他还断言，一些被广泛认为是黑天鹅的事件被“错误地贴上了标签”。在他看来，他们是可以预见的。根据我们在化学过程安全中处理低频（罕见）高影响情景的经验，我们被问及是否应将当前的 COVID-19 大流行归类为黑天鹅事件的意见。尽管尚未预测这种特定 SARS-CoV-2 冠状病毒的出现时间和确切性质，